SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c26a0843c67c2cb1900e385ca3553287dd05c91108bf77d2c14f233a3a30c0d3' 
  AND token = 'L1AhKldnmDzwTwrKxdYyPm7k/qXRA28dBhQ3nVIcoy8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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