SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2eb9b542e30ddf640a0827a3945d9a7436267bbbe8f46caeda93c44526a9ccf1' 
  AND token = '2I/UmZ6UEjh4nGn+mI4MOezpw/c6KVfQZ0aX4eb+yY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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