SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '151ffd1f6cc330ff1ea779478346d426a77ac986954f113bd742d854db5478a3' 
  AND token = '+lNqe1T+mpM0eTpjPi/YkjlLyZAeD/X1WoRqFAEDLYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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