SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2881f198b26ce310d3778111544983a3a59634da2ff591170de3c1129f23c533' 
  AND token = 'pgbBO+wIcrtIjnOy+hd7S8vAaCEaq6YwYQnUXlUFx2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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