SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d1b208ae1652576830e2a0919c531661b7e4d343eb0868e32127ad4dccebf7c' 
  AND token = 'KQmoncXCV4zot2kq8b3OcOqMtneaEqgqGMGPOkVNB4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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