SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13e9cbdfc9131189a37d4cee79d108b67ff68af0461c270d31dc47685cbcbde5' 
  AND token = 'ZqXosH8Tj64NPnJX5GRXOdQyO8WytCmIq2/cqeomeKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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