SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd018a185a6f1670901c11a60bc823dc862ba19992b869228a28de86b6523bad4' 
  AND token = 'x9atS66cLm/0uH+AJpIg7kiYtvLUzJigiCrVAIWrZs8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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