SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a1858b4b8284530652df28ece91f44def9abcaddca38fe6fd09d6982c6702b1' 
  AND token = 'q/oPOHFVxXq8zAGTCisD85QqaM2dX1WPEx85yf+ooQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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