SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc49c305d4c026571cb1e4cf4c79231b538fc8bc303c13cb0b7575f8a77489b2' 
  AND token = 'j/iKOOFYoqDoxhhrKarzBEZlevGRSNqCHGAqmjzy6TQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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