SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b0254776719f4615f7d91ed8a2bab0d2683c44d25003381ae3e93132e19d2e7' 
  AND token = 'z9yEt9KE716OtZBMtUaVhmIIAhfQ4Qd4cFvKdBNFSMk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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