SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53ff1f8bf92dae380ead7ed242a422367cef435c6b0751ddc8a1cf4111abcee8' 
  AND token = 'EWhRo99g9n3vecTGREn/TyXZUXPK6EL6ATHPEyduA/E=' 
  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"
    }
  }
}