SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59ab1464b9c07a7fe792f30928b750636cd967a243fd9774b25fad5ebfd25da1' 
  AND token = 'aZKJBRvtF/xFmA2ZzVG5iUiZR3aYqsYCtQFaK1w2lNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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