SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4146c1b163de782b66acf1bb7d0d5e0b16188be03b5828a540800840be34ee54' 
  AND token = '0EKwofyGpojol6t6jalTx7MeGzoMKJWzDcM+w/K/WJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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