SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '80be28e8aaac3a107b2be18d2e4ab07d541137e9827ad930e9cff4a536c97761' 
  AND token = 'PxvBr7QmaDZjq19ifw7U2O/51vltNicycSenmntAZ0Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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