SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1156094422c9c2bce0765b744ac16592455a3ad0445d5d49eae905fcecacd5b' 
  AND token = 'ARbaDa6YwtbwljUKf3+sCCVwOoNRIh7Pp8CW7ktS2x4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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