SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6245fee962ee176d9bc74f5eca3e4f4bd4274202aedce1158c4d6296c4cfc9c2' 
  AND token = 'gq10Tdog+vFjAhE9FEwtKKM1i5DQ3kcF/6S81auUFF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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