SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b5f313690ad9200c5cac8afa36355bfaf54d4d740710a4011dd66af7c241d2c4' 
  AND token = 'NkacoWcoXFmnq4zaUcPjxEuhaTw0+kB1PjYR6tFmB74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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