SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd989a2f5063f34e8a693db2c99a6ad46fa5260b3171cf886d3d60da879e98110' 
  AND token = 'ZzM1m7fQhuSMTOgV/zGQUYUwL+tqi31T1PSRyOoR8sg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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