SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d4c848a874fb8fe11827be8f8088ee79d080974990bf969405b3710db51e398' 
  AND token = 'rM3U1aS2NmQaBmAt1aCMLZLQozovhRaJsEzRHhn0KNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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