SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea4736f2371cad16a2dfdf9b122491c96d157314c663e8d67f1a08991d38a21d' 
  AND token = '5kQ51HW2Q+ISXky1l98/8eNfZ6E6x2O2yaY81jEudqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

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