SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7f1d2c322ba44f8976a3a869adcb3d7f1b0818dc66bad82c9d1aebdd7a036341' 
  AND token = 'mx8znz4CwAlMeGzkwPsyR52SSevUB0XoMj2qhq697mg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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