SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b7a58fca577900abaea296d2234230ca73cc92a8ff332012394ac09974da64a' 
  AND token = 'LNdMZG9NBt9PdNNau8IThQbFB8DTAssK2B+ll1Giurg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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