SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb99ece57f1dbbf677099900a30773540388f815f55f869e407f83565c52951c' 
  AND token = 'b5mi+QDmwo7ECnsbKm55Y1ILDB6hJWtliYfEHt5O9Do=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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