SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ff94c02796c875ca89facc1c399bf68e9d11393dd3b20a8e2cdb89ac6682e062' 
  AND token = '+mgv5uWyloCddSjIAuBiUlFdwOfV/yyxQL1hNO+Ijw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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