SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e73ad0136a0f048444ba601dc68ae00fdb651acace1a74f7dce838bb83a7a66' 
  AND token = 'SimTTmbFcPlP3BPqAApKblemyx2oWrYaYZolL9Jkcd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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