SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbe5764d731fda12bb68e11ba4c2ca3239283238d13783f43f659c44ad89f4d4' 
  AND token = '4JGkAO+TK26O/gF5I9HSxeKhSRUzO4/BZzZ00tkwtkA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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