SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1631d0952cb025118232887d996a059b547ad4772452d4dc589b212444f09334' 
  AND token = 'lJ2c157Us4vbkRcFovT8GMkB9WY+fR20qYDJdpRoFi4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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