SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65388e2b0bd961ef5109ca79d6110f9638d2e273df36751995a89d581b7dc2fb' 
  AND token = 'BbRsxgN1ys4yKFnmxg5FsciNHIvjOao7kahXJ2SUaMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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