SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65170021ae6d2d471736126bbf464b7552e98c5ff319bb8075e85a991af6b3d1' 
  AND token = 't+WLGCsTJmR+7XrxmzwW2y0Rx8oZS3/iK9McVnyU9/c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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