SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cdfb83414c0fedcecc315edfe6c7f7fc809fca52c26ec57725a617b5b4872f4' 
  AND token = '9BWhyb5PGYKURV+n3Cf1coqV3D01Uf142EQhY+fxOag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}