SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a355f35171ba2c21239c581e55594575bd7fbf8a0120aa0b133bd30b6fc3bd0' 
  AND token = 'ktcscHK9ehH1f4t3y9EYFnNcjqEOaaJ0gp/+VZABXCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}