SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '36fcebe3a75bf2cb258ad363843c3b7bfd5e5739249d70a50625e95cbcaa0c46' 
  AND token = '0M8dkoN6f3VGj/9HHB8g95S0KO3B0eh4vY8Ra/2Txvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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