SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a9a3bcf9a3844f99bae4b71cbd236718548ebd3b35ac6b9c379acea245cf60d' 
  AND token = 'wixoofo7nfflIiTjS80KwSxlXzDtsZCWIq3MefLZtsk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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