SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88424280bd8a1bbe05c8199a20a866da3f67a2c61636164de10e995b814a7071' 
  AND token = 'VXYscB1QBM/D3QUjj34l/+w8zbblH9QiQdkw8nLoHJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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