SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2ce96ad502bf458814a7005c2cff6a788dac8d7f215113fefdfa3fa4a95088eb' 
  AND token = 'ePmjJUAjh2yorgTonJUnPpHGv3GUFUYWLduxjj8CYjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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