SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3557567162f5121171512638f6674d19c1ebabd7c75175ab9298982e532621b1' 
  AND token = 'rxamA0y6lpNm9TnUG7SzSFPtq30QVdLwELc7fVZlINs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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