SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '851b95237fccb7166b3eb4152b7ab1e307ee8d396550f6a7aff1982fa996d7fc' 
  AND token = 'EGGnz1aLnghePCmx5U6sl5XwVrWBRJO+gmRMxCkgIts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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