SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bd557c249c0275ecd4397495a21abe77faa69c5f8e36171d287b4263811e308' 
  AND token = 'jdJPpK9h4VNbbDhm6yiW58WE7RzB5XBvTLB62XmHouo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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