SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a7296156308f46f1c9f59a55369ac64dde0d6236fec912e5e598d37c4c3df417' 
  AND token = '9lpgKm4kZQAmLoeyWhYrz/kXNdA8XnlZ2+8DbcvqDZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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