SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d535d385d63cffd44399af9d0bb617efef795d33084664171db7218626b9185' 
  AND token = '7B87AMWmY5hssNTjBbSbF+QdnVYZGTTPIlL6gy0ssao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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