SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e076e200e4ec98d6d31524b6fa1b36b195fca4ec8e9ae9cc356b4988622d0a56' 
  AND token = 'kU6j/G9ncvT3tUanSE7TgtmpwGM2vcSJZD2nb+DRgRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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