SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf8b57aacfa6a849d76003513ded68901e84c5fc101a54478632100a479e3295' 
  AND token = 'Tm8mZtS12lBTQHMtkxoz/WP8pDmNvPLfWzmu7KZxMIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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