SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b63076b659c889b4cd1ae388be4efec4b76e8d53e3b772dd3bc91e052632903' 
  AND token = 'FN+wz6UAxR6KFzIIq1XmpFPzXDVrVujdvuLrGWo8K6I=' 
  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"
    }
  }
}