SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e50e50b217c60e8668029e8b5bbad0d6d0a7539b9daf658510dbd74d4f8d447' 
  AND token = 'FgnRVrdlgsdosvrS2/pJVgKhe01vUa7eyNPP3/0VFTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}