SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6ae86ac4ae2dc6cd1258d11c2f1c5fb81d1697db64f426f6f230dc946072b00' 
  AND token = '6Wx86QuCifGpKHdexVCylEZBBh68N213341bwAZ16NE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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